John johnson



UNTED STATES JOHN JOHNSON, OF NEW YORK, N. Y.

APPARATUS FOR POLISHING THE PLATES USED IN TAKING LIKENESSES FOB, OTHEROBJECTS IN' TVI-)ZICH SUCH PLATES ARE REQUIRED.

specification of Letters Patent No.

To all whom t may concern Be it known that l, JOHN JOHNSON, of the cityof New York, in the State of New York, have invented a new and usefulImprovement in the manner of and apparatus for polishing the plates usedin taking daguerreotype likenesses or other pictures of a like kind andwhich apparatus and manner of procedure may be applied to the polishingof other articles; and I do hereby declare that the following is a fulland exact description thereof.

The polishing of the metallic plates, is to be eHected by means of afiat disk, attached to the mandrel of a lathe, or to a spindle ormandrel made for the purpose, and running in the manner of a lathemandrel; for plates of the size ordinarily used for daguerreotypelikenesses, a disk of tive or six inches in diameter, is sutlicientlylarge; but for larger plates the size must be correspondingly increased.These disks are converted into Vrolishing buffs, by coveringthem withcotton velvet, corkwood, leather, or other suitable material, which maybe charged with pumice-stone, rotten-stone, rouge, powdered charcoal, orother polishing substance. So far there is not anything new in theapparatus used by me; the novelty consisting in the manner in which theplate to be polished is held against the' polishing disk, or buff. lnthis operation l use a flat piece of metal or other suitable substance alittle larger than the plate to be polished, and around the edge on oneface of this l affix a ledge or rim, within which the plate is to bereceived, said ledge not rising as high as the thickness of the plate tobe polished; this instrument l will call my plate holder. On the otherside of this plate holder and at its center l affix a socket of metal,which is to receive a pointed wire or rod, upon which it may revolve,said wire, or rod, being furnished with a suitable handle. At the frontof the polishing buff l place a rest, upon which to sustain the rod orwire and upon this it is to be moved back and forth, so as to vary itsdistance from the center of the buit. rIhe plate to be polished beingheld against the bnii, by means of this apparatus, and the spindlebeingrapidly turned, the plate also 2,391, dated December 14, 1841.

will revolve rapidly, and by this motion and by the gradual shifting ofthe rod toward and from the center of the buil", the polishing will beeifected in a very short space of time, and that without the producingof lines upon the face of the polished metal, which can scarcely beavoided in any of the ordinary modes of procedure, while at the sametime the polishing is performed with much greater rapidity than in anyother way.

In the accompanying drawing Figure l, represents the spindle, buff, andrest; A being the spindle, furnished with a whirl B. The buif is shownat C, and the rest in the front of it at D. Fig: 2, represents the faceof my plate holder, surrounded by ledges a a.. Fig. 3 is a sectionthrough the middle of said plate holder; E, being the socket which is toreceive the point F, of the wire or rod, Fig. 2.

The operation of this apparatus will be similar to that of Bogarduseccentric mill, but it differs from it both in the object for which itis employed and in the means of employing it; the object being tooperate upon one of the revolving bodies, and the difference in themeans consisting in the rendering of the body, or plate, to be actedupon capable of being shifted toward and from the center of the buff oroperating disk.

Having thus fully described the nature of my invention and the manner ofcarrying the same into operation, what I claim therein as new, anddesire to secure by Letters Patent is The polishing of metallic platesfor daguerreotypes or other purposes, by means of an instrument such asI have denominated a plate holder in combination with a wire or rod,received within a socket upon which the said plate holder, and thecontained plate, may revolve when held against a polishing disk or budand by which it may be shifted toward or from the center of said bu, thewhole apparatus being arranged combined, and operating, substantially asherein set forth.

JOHN JOHNSON, Witnesses:

Trios. P. JONES, M. JONES,

